Projects -
Overview

A major part of our research work is dedicated to the
causal analysis of competition,
certainly one of the most important interactions among plants.

In this connection we particularly focus on the
importance of disturbance for the
stability of certain successional stages.

A special case of competition is the introduction of
alien plants into indigenous
vegetation. Traits and strategies of various successful alien plants are
presently investigated in our group. This research (including ecophysiology as
well as population ecology) not only helps to understand the necessary
ingredients for successful colonization of an already occupied area but
provides also valuable knowledge for an effective control of alien plant
species

One of the more prominent interactions between higher
plants and other organisms is herbivory.
During previous years members of our group analyzed the consequences of the
herbivory of leaf-cutting ants for the tropical rainforest ecosystem.
Presently we start investigations on the importance of herbivory for the
competitive strength of selected sand dune species.

In order to integrate our results, but also as an
experimental tool, we presently develop spatially explicit models, which simulate the formation of
vegetation patterns and their dynamics based on our experimental data. This
work is still in its beginnings and is done in cooperation with
mathematicians, informatics people and colleagues from the Environmental
Research Center (UFZ) Leipzig.

Together with colleagues from Utah State University
and the University of Bayreuth we developed and parameterized
canopy photosynthesis models, which calculate photosynthesis and
water relations of target plants as a function of the surrounding vegetation.
The main issue here is the modelling of the light environment within the
canopy and the assessment of how physiological functions of plants are
dependent on the amount and the orientation of structural elements of the
canopy. Recently a photoinhibition model was added. Besides other
applications, these models are used in a number of studies dealing with light
competition.

The presence or absence of a plant species (i.e. its
competitiveness) in a certain habitat is frequently a function of particular
stress adaptations. This is the background of a
recent research project on plants of the Mediterranean. Here we
compared differential adaptations of sclerophyllous vs malacophyllous species.
A subroutine for our canopy model
was developed, which allows to quantitatively assess the effect of
photoinhibition on short and long term carbon gain of these species.

Composition and spatial distribution of vegetation are
major factors, which affect the fluxes of carbon and water at the ecosystem
scale.